1. Field of the Invention
The present invention relates to communications networks and particularly to the management thereof.
2. Related Art
Competitive advantage can be gained by communications network operators %through the services that they offer and the efficiency with which they manage those services. Targets that a network operator might aim for include reduced charges, improved quality and increased customer control of services. Part of the networking infrastructure that might facilitate these customer offerings may well be the Global Multi-Service Networks (GMSNs) which enable network operators to offer their customers:
Rapid service provisioning PA1 Controlled quality of service PA1 Integrated services PA1 Regulated control of network services PA1 Multi service provision PA1 Multiple vendors PA1 Multiple administrators PA1 Flexible service management PA1 Dedicated international private leased circuits PA1 Routing controlled by PA1 Customer controlled dialling plans PA1 Grade of Service (blocking probabilities, bit error rate, error free seconds etc.) PA1 Target and guaranteed minimum provision times PA1 Target and guaranteed minimum cessation time PA1 Target and guaranteed minimum repair times PA1 Target and guaranteed service availability PA1 i) "Distributed Artificial Intelligence" by M Huhns, Volumes I and II, Published by Pitman, Morgan, Kaufmann in 1987; PA1 ii) "Fundamentals of Distributed Artificial Intelligence" by D G Griffiths and B K Purohit, published in British Telecommunications Technology Journal, Volume 9 No. 3, in July 1991; and PA1 iii) "The Role of Intelligent Software Agents in Integrated Communications Management" by D G Griffiths and C Whitney, in the same issue of the British Telecommunications Technology Journal. PA1 A large range of services PA1 A wide range of customer types PA1 Complex SLAs with financial penalties PA1 Network(s) spanning more than one country
Ideally, these facilities will be offered with the same availability as voice connectivity is today but providing many new features together with mobility and movability of customers.
To enable network operators to offer their customers the extensive flexibility, quality and control the above demands, GMSNs will need to support:
The complexity and operational characteristics of GMSNs are expected to impose requirements beyond the capabilities of current network management approaches. Not only will the GMSNs have to provide services to the customer according co contract but price and performance will have go be optimised at the same time for the network operator.
A Multi-Service Network (MSN) is any network that is capable of supporting a range of services. The Pan-European Integrated Broadband Network investigated in a European RACE initiative, and referred to in the paper "Broadband Communication Management--The RACE TMN Approach" presented by R Smith at the IEE Broadband Conference in London in 1990, is an example of a MSN based on the Asynchronous Transfer Mode. There are networks currently available in the USA which are examples of MSNs that use more conventional switches (e.g. DMS 250 from Northern Telecom). Such networks can be used to transmit voice as well as data. The data can be split into various transmission rates, for instance from 19 kbits/sec up to 40 Mbits/sec, so that a range of services from file transfer to real time video can be supported. Furthermore, the trend in such networks is towards global networks where the MSN can span many countries, hence the emergence of GMSNs.
Initially at least, the intended customers for MSNs are expected to be large corporate users, perhaps with many sites situated world-wide. Such a customer will require a network which appears to be a private switched network, providing at least the functionality that they enjoy from the international private leased circuits. In fact the service can be supported by a number of underlying networks, possibly from many different network operators. This arrangement is known as a virtual network.
Service Level Agreement (SLAs)
These companies often entrust a large proportion of their world telecommunications requirements to one service provider by contract. It is extremely important that they are provided with the level of service specified in their contract. The exact definition of the service is specified in a Service Level Agreement (SLA). The range of services available is potentially extremely large, and each service can be further customised since each service has a range of options. Example services include:
time of day PA2 calling identity PA2 originated location
An example of the latter is where a user needs only to dial 111 to get through to the relevant sales department, regardless of where the call is originated geographically in relation to the sales department.
A SLA can be expected in general to include:
Working in object oriented software technology, models for services and SLAs have been developed by the International Standards bodies (OSI/NMF and CCITT). These provide Generic Managed Object classes that define services and SLAs. The concept of a feature Managed Object is introduced to define a component of a service that can be offered to the customer. The logical numbering scheme permitted in Intelligent Networks is an example of such a feature. Features can be "nested" so that one feature is a component of another feature. The mapping from the feature to the underlying network resources is also defined in the feature object. In an intelligent network of known type, having a structure including a service control point (SCP) (or other means) for making reference to service and/or customer data, the service control point (SCP) would typically be a resource on which many Features (e.g. logical numbering, time-or-day routing) depend.
Information about billing, fault handling and performance criteria may also be held within a feature, so long as it is common to all instances of that feature. It is possible for instance though that the performance criteria of some features will depend on the use to which they are put.
A SLA is then defined in terms of the component features that support the service in question. In addition to this, information about the contract and a description of the service covered by the SLA is also kept. A SLA will typically refer to a number of features, which in turn may refer to other features and resources. To support this relationship a number of dependency relationship types can be defined (supports, depends-on etc).
Multi Service Network Management
The customer is also likely to require the ability to manage their own virtual network: services can be requested, altered and ceased by the customer from on-line connections to the service provider's equipment.
All this complexity makes network management an extremely difficult matter, particularly where reconfiguration is required, and particularly in the light of SLAs.
Providing Multi-Service capabilities across more than one country is likely to require considerable capital outlay. To make such a network viable the operating cost has to be kept within tight constraints. To meet this operating cost constraint, extensive automation of management functions in the network will be very attractive, if not essential.
According to embodiments of the present invention, this automation will be achieved at least in part through the use of Cooperating Intelligent Software Agent technology. The basis for such technology is described in general terms in various publications including:
The relevant content of each of the above is herein incorporated by reference.
Particular aspects of network management which might be automated by means of embodiments of the present invention, together or separately, include the establishment and restoration of routes in an underlying physical network while maintaining customer requirements satisfaction.
Lone Term Service Provisioning
Service provisioning is a requirement of any telecommunications operator. Service provisioning for a GMSN tends to differ from conventional networks because of the following characteristics:
It is likely to be a requirement that when a customer requests that a new service be provided, they should receive a quote and an indication of timescales within a fixed time. The customer puts in a request for a new service (possibly via a management terminal for existing customers, or through a negotiator for new customers) and will expect to be told how much the service is acing to cost and when it can be made available. If the service cannot be supported by the existing network configuration then some reconfiguration is clearly required and may well involve the provisioning of new equipment.
Real-time Network Reconfiguration
When a network element fails, a number of services could be affected. They could fail completely or they could fail partially but their quality of service may drop below that defined in the customer SLA. When such faults occur, alternative ways (through network reconfiguration) must he found for re-establishing the same service.
In a conventional network (e.g. as provided to date in the UK PSTN) such reconfiguration is controlled by routing tables in the switch (e.g. System-X exchanges). The switch automatically attempts to re-route around problems in the network through control actions from a central operations unit. This routing takes no direct account of the type of traffic that is being routed and, as a result, all traffic is treated equally.
In a more complex network (such as GMSNs), where there is a wide range of services and a large number of different customer types, this simple approach is not so viable. It is no longer safe to assume that all network usage is of equal importance.